/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
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 *
 *
 *
 *
 *
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 */

package java.net;

/**
 * This class represents a Network Interface address. In short it's an
 * IP address, a subnet mask and a broadcast address when the address is
 * an IPv4 one. An IP address and a network prefix length in the case
 * of IPv6 address.
 *
 * @see java.net.NetworkInterface
 * @since 1.6
 */
public class InterfaceAddress {

  private InetAddress address = null;
  private Inet4Address broadcast = null;
  private short maskLength = 0;

  /*
   * Package private constructor. Can't be built directly, instances are
   * obtained through the NetworkInterface class.
   */
  InterfaceAddress() {
  }

  /**
   * Returns an {@code InetAddress} for this address.
   *
   * @return the {@code InetAddress} for this address.
   */
  public InetAddress getAddress() {
    return address;
  }

  /**
   * Returns an {@code InetAddress} for the broadcast address
   * for this InterfaceAddress.
   * <p>
   * Only IPv4 networks have broadcast address therefore, in the case
   * of an IPv6 network, {@code null} will be returned.
   *
   * @return the {@code InetAddress} representing the broadcast address or {@code null} if there is
   * no broadcast address.
   */
  public InetAddress getBroadcast() {
    return broadcast;
  }

  /**
   * Returns the network prefix length for this address. This is also known
   * as the subnet mask in the context of IPv4 addresses.
   * Typical IPv4 values would be 8 (255.0.0.0), 16 (255.255.0.0)
   * or 24 (255.255.255.0). <p>
   * Typical IPv6 values would be 128 (::1/128) or 10 (fe80::203:baff:fe27:1243/10)
   *
   * @return a {@code short} representing the prefix length for the subnet of that address.
   */
  public short getNetworkPrefixLength() {
    return maskLength;
  }

  /**
   * Compares this object against the specified object.
   * The result is {@code true} if and only if the argument is
   * not {@code null} and it represents the same interface address as
   * this object.
   * <p>
   * Two instances of {@code InterfaceAddress} represent the same
   * address if the InetAddress, the prefix length and the broadcast are
   * the same for both.
   *
   * @param obj the object to compare against.
   * @return {@code true} if the objects are the same; {@code false} otherwise.
   * @see java.net.InterfaceAddress#hashCode()
   */
  public boolean equals(Object obj) {
    if (!(obj instanceof InterfaceAddress)) {
      return false;
    }
    InterfaceAddress cmp = (InterfaceAddress) obj;
    if (!(address == null ? cmp.address == null : address.equals(cmp.address))) {
      return false;
    }
    if (!(broadcast == null ? cmp.broadcast == null : broadcast.equals(cmp.broadcast))) {
      return false;
    }
    if (maskLength != cmp.maskLength) {
      return false;
    }
    return true;
  }

  /**
   * Returns a hashcode for this Interface address.
   *
   * @return a hash code value for this Interface address.
   */
  public int hashCode() {
    return address.hashCode() + ((broadcast != null) ? broadcast.hashCode() : 0) + maskLength;
  }

  /**
   * Converts this Interface address to a {@code String}. The
   * string returned is of the form: InetAddress / prefix length [ broadcast address ].
   *
   * @return a string representation of this Interface address.
   */
  public String toString() {
    return address + "/" + maskLength + " [" + broadcast + "]";
  }

}
